Today, pillows come in a wide variety of forms. Traditional, non-orthopedic pillows typically consist of rectangular, fabric enclosures filled with feathers, down, chipped foam, or a polyester fill. These pillows may be shaped by the user to provide reasonably adequate support for the user while the user falls asleep. However, many people suffer from an uncomfortable night's sleep because of the inadequate support that their head and neck receive while using these traditional pillows throughout the night. This is because traditional pillows either have a body that is so soft that the neck support area compresses to result in no support, or the body is so firm that the head sits considerably higher than the shoulders of the user, resulting in an abnormal sleeping position. Chronic neck pain or stiffness and a tense upper back are often the result of these inadequate forms of support these traditional pillows provide.
For this reason, many people turn to orthopedic pillows in an attempt to furnish them a more comfortable and healthier night's sleep. Orthopedic pillows are designed to provide users with proper support and alignment of their head and neck. A multitude of different orthopedic pillow designs exist, many of which offer different methods for improved positioning of users heads and necks as they sleep. The many different cervical pillows do this to one extent or another through different designs. Cervical pillows in general work by providing a raised surface under the back of a user's neck, thereby supporting the neck forward and allowing the head to fall back, thus maintaining the lordotic neck curve while the user is back-lying, and to support the head and neck in the side-lying position. This action provides support to underlying muscles in the cervical spine region that tend to be weak, and it correctly aligns the spine, head, and neck. A well known and exemplary model of a cervical pillow is the Wal-Pil-O.RTM. pillow by Roloke Company, which utilized U.S. Pat. No. 3,521,310 issued to Greenawalt. This pillow allows the user four different combinations of head and neck support in both back-lying and in side-lying positions.
Many of these orthopedic pillows use a resilient foam material, such as a flexible polyurethane foam, to provide the necessary support to the head and neck. Another foam used in manufacturing the pillows is viscoelastic memory foam. Viscoelastic memory foam is designed to retain the shape or form of the user's head as the user sleeps on the pillow every night. This function of retaining the shape of a user's head aids in providing a more comfortable sleeping experience for the user.
One major drawback of ordinary polyurethane foam cervical pillows is that they typically have to be broken in before the pillows achieve their greatest level of comfort. "Breaking in" a pillow simply refers to the process of repeatedly compressing the foam of a pillow during its initial usage. The compression is caused by the weight of a user's head sleeping on the foam night after night. This repeated compression of the foam every time the user is sleeping compresses the internal structure of the foam and pushes air out from within the structure. The polymers of the foam tend to "remember" this compressed structure, and this "memory" makes the polymers tend to bias towards the compressed structure. Through this breaking-in process, the foam becomes softer and more resilient in the area of the compressed structure, and because the area of the compressed structure corresponds to the area where the user's head is pushing down on the foam, the foam is thus "conforming" to the shape of the user's head.
This break-in period can last anywhere from several days to a week or more before the foam adequately and comfortably retains the shape of a user's head. This long of a break-in period may be unacceptable to potential users who require the head and neck support these pillows offer, but are unable to endure the stiffness of a non-broken-in foam due to their medical conditions. For instance, users that have chronic or acute neck disorders, or that have suffered a recent head trauma or neck injury typically cannot withstand any length of a break-in period.
Accordingly, there is a need for a foam, orthopedic pillow that provides comfortable head and neck support, correctly aligns the spine, head, and neck, and requires no break-in period.